Calculators
House Hacking Calculator
Calculate your net housing cost when renting out other units or rooms, and the saving compared with renting.
- Runs in your browser
- Nothing uploaded
The tool
Enter your numbers below. Results update as you type, and nothing leaves your browser.
Everything you enter stays on your own machine. Nothing is sent to us or to anyone else, which you can confirm in your browser network tab.
What people use it for
- Evaluating a duplex, triplex or fourplex
- Deciding whether to rent out spare rooms
- Planning a first property purchase
- Comparing house hacking with renting
About this tool
What the House Hacking Calculator does
House hacking means buying a small multi-unit property or a home with spare rooms, living in part of it and renting out the rest. Rent from the other units offsets the mortgage, so the owner’s real housing cost can fall well below market rent.
Formula
- Rental income = units × rent × (1 − reserve)
- Net housing cost = housing payment + costs you cover − rental income
- Saving = alternative rent − net housing cost
Worked example
Using the starting values in the calculator above:
| Input | Value |
|---|---|
| Total monthly housing payment (PITI) | $4,800 |
| Units or rooms rented out | 3 |
| Rent per unit | $1,600 |
| Vacancy and maintenance reserve | 10% |
| Utilities and costs you cover | $300 |
| Rent you would otherwise pay | $1,800 |
| Result | Value |
|---|---|
| Your net housing cost | $780 |
| Monthly saving vs renting | $1,020 |
| Rental income after reserves | $4,320 |
| Share of costs covered by tenants | 84.7% |
How to read the result
Owner-occupier loans for two- to four-unit properties often allow smaller down payments than investment loans, which is what makes house hacking accessible.
Living with tenants means being a landlord at home; screen carefully and use proper leases.
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Questions
Questions about this tool
The things clients actually want to know — costs, timelines, ownership and what happens after launch.
Living in part of a property and renting out the rest to reduce or eliminate your own housing cost.
Yes, when tenants' rent exceeds the full housing payment and costs.
Two- to four-unit buildings and homes with separate rooms or an accessory unit.
Free strategy session
Let’s build something worth finding.
Tell us where you want the business to be in twelve months. We will come back with a costed plan, a realistic timeline, and the numbers we expect to move — no obligation, no jargon.
- 30-minute call, no pitch deck
- Fixed-price proposal in 48 hours
- You own everything we build
Talk to a developer
Not a sales team
- Response time
- Within 1 business hour
- Where we work
- UK, USA & the Gulf
- Contracts
- No lock-in, monthly rolling
- Working since
- 2023